Mother-to-child transmission of HIV accounts for over 15% of new annual HIV infections worldwide (UNAIDS, 2012). Every year, approximately 300,000 infants - mostly in sub-Saharan Africa- contract HIV from their mother during pregnancy, childbirth, or breastfeeding (UNAIDS, 2012). AIDS remains one of the leading causes of death for children under five years in sub-Saharan Africa (H. Khan, Michaels, & Eley., 2006). Thus, preventing perinatal HIV is an essential component to curbing the global HIV/AIDS pandemic and decreasing global infant and child mortality rates. Fortunately, biomedical and behavioral interventions known as prevention of mother-to-child transmission (PMTCT) exist and can reduce the risk of a mother passing the virus to her infant from about 40% to less than 5% (WHO, 2010a). Over the past decade, these interventions have become widely available throughout most of the world, including countries such as Zambia. However, the number of HIV-positive mothers adhering to PMTCT protocols is not increasing as fast as health professionals would expect (Msellati, 2009). In Zambia, one of the countries with the highest global HIV/AIDS prevalence, adherence to PMTCT protocols remains suboptimal. Approximately 10,000 infants (11% of those exposed) contract HIV from their mother each year (UNICEF, 2012a). The reasons for non-adherence to PMTCT protocols among HIV-positive mothers in countries such as Zambia remain poorly understood. In order to address this gap, the applicant proposes a mixed methods dissertation study, including a quantitative survey and qualitative in-depth interviews with HIV-positive mothers in Lusaka, Zambia. Women's low power within couples has been established as a risk factor for poor adherence to antiretroviral therapy (ART) (Human Rights Watch, 2007; Maman, Campbell, Sweat, & Gielen, 2000), but has not been associated with non-adherence to PMTCT specifically. This study will test if women's low power within couples decreases PMTCT adherence and if HIV status disclosure to the husband/partner is a mediating factor in the relationship. In addition, through qualitative work, it will contextualize he behavioral and social aspects of HIV-positive mothers' PMTCT adherence in Lusaka. After completion of this research study, the applicant will have strong content knowledge of perinatal HIV prevention and gender power imbalances, which are some of the key focuses currently in global health. The training plan will also enable the applicant to gain strong methodological skill with advanced quantitative and qualitative training through workshops/forums, conferences, courses, and collaboration with her sponsors and consultants. This will extend the applicant's potential for a productive global health research career targeting HIV/AIDS, gender inequality, and maternal and child health.